An Orange County Superior Court jury has ordered Ford Motor Co. to pay $127.8 million in damages to a teen-ager who suffered severe burns over 95 percent of his body when the gas tank of a 1972 Pinto exploded.

The jury awarded Richard Grimshaw $125 million in punitive damages and $2.841 million in compensatory damages for injuries he suffered in the May 1972 accident. Grimshaw, now 18, has undergone 52 operations since the accident, in which the driver of the car, Lily Gray, was killed. Gray was a neighbor of the Grimshaw family.

Gray's family did not sue for punitive damages but was awarded $665,000 in compensatory damages from Ford for wrongful death.

"This is probably the loudest noise that the jury has made in any civil suit in American jurisprudence," Mark P. Robinson, attorney for Grimshaw, said after Monday's verdict.

He said he expected Ford to appeal.

In Dearborn, Mich., Ford said the California jury's award "is so unreasonable and unwarranted that it will not be upheld."

"Punitive damages may be assessed only in cases involving intentional injuries or conscious and willful disregard of the safety on consumers," vice president Henry Nolte Jr. said. "We believe these factors were not present in this case and that imposition of punitive damages therefore would not be justified."

The entire passenger compartment of the Pinto which Gray was driving and in which Grimshaw was a passenger ignited when it was hit in the rear by another vehicle which was moving at about 35 mph. Evidence at the seven-month-long trial showed that because of faulty welding, the gas tank was punctured by the impact, and the ignited gas leaked into the passenger compartment.